The subject matter disclosed herein relates to on-load tap changers (OLTCs). Specifically, the subject matter disclosed herein relates to a fault gas alarm system for an oil-filled vacuum-type OLTC.
As is known in the art, an on-load tap changer (or, OLTC) is used to change the tapping connection of a transformer's winding while the transformer is energized. Various forms of OLTC devices exist in the art, however, aspects of the invention are directed toward oil-filled vacuum-type OLTC devices.
In these oil-filled vacuum-type OLTC devices, gas is not present in the vacuum during the normal (or, non-alarm) state. When gas (e.g., hydrogen and/or carbon monoxide) appears above trace levels in a vacuum-type OLTC, a problem typically exists. Current approaches used to monitor the presence of gas in oil-filled vacuum-type OLTC devices involve elaborate and expensive monitoring hardware, and are not specifically tailored for oil-filled vacuum-type OLTC devices.